Although the idea for developing synthetic hydrocarbon fuels has been discussed for at least the last 30 years, there has not been a need to produce them because of the availability, ease of production, transportation, and processing of fossil fuels. However, the worldwide fossil fuel market is changing due to a number of factors, including steadily increasing worldwide energy demand, increasing concentration of production in oil producing regions, and increasing emphasis in oil dependant countries on the importance of energy supply.
There are several disadvantages to using fossil fuels. First, there is a finite amount of fossil fuels available which, once used, cannot be regenerated. Additionally, hydrocarbon fuels made from fossil fuels may contain highly undesirable sulfur, nitrogen, and aromatic compounds. When these fuels are burned, sulfur, nitrogen, and particulates are released into the air, which leads to the formation of acid rain and smog. More recently, concern has focused on the impact of carbon dioxide emissions from fossil fuel combustion as a contributor to global warming.
There are several well-established processes for direct hydrogenation of gases such as carbon monoxide or carbon dioxide to produce hydrocarbon fuels. One of the most successful was developed in Germany in the 1920s by Franz Fischer and Hans Tropsch.
In 1938, early German plants produced approximately 5 million barrels per year of diesel oil and gasoline using the Fischer-Tropsch process, which reacts carbon monoxide and hydrogen over a catalyst to produce liquid hydrocarbons and water. The problem with this and other methods is that they use fossil fuels such as coal or natural gas to produce the carbon monoxide. The use of such fossil fuels as the primary feedstock is accompanied by many of the same drawbacks as the production of fossil fuels such as finite supply and emissions.
Therefore, it can be seen that there is a long-felt need for a production system that recycles the products of combustion into hydrocarbon compound fuels. It is to such a system and processes for making hydrocarbon compounds that the present invention is primarily directed, with emphasis on energy efficiency.